Y Combinator Directory

YC says it now runs its three-month program four times a year, in the winter, spring, summer and fall. For most of its history there were two batches a year: Summer 2005 was the first, and every year from 2006 to 2023 had a Winter and a Summer batch.

The change came in two steps. In August 2024, YC announced its first-ever Fall batch, starting in San Francisco on September 29, 2024, with Demo Day in early December. In January 2025 it added a Spring batch in the April to June timeframe, saying more frequent batches make the timing more likely to work for founders and that the pace of change in AI is leading more people to start companies. In the directory, Fall 2024 has 94 companies and Spring 2025 has 143.

YC publishes dates batch by batch. This is what its own pages said on September 13, 2026:

Demo Day dates are from YC's post on 2026 Demo Day dates. For later batches, check YC's site before planning around a date.

On September 13, 2026, YC's apply page was taking applications for Winter 2027, which runs from January to March in San Francisco. The on-time deadline is November 2 at 8pm PT, and on-time applicants get a decision by December 11. The directory listed 51 Fall 2026 companies so far; that batch's Demo Day is December 2.

One Winter 2027 company already appears in the directory. It is shown apart from the 2005 to 2026 totals above.

It depends on the year. The 2026 batches list 199 companies (Winter), 193 (Spring) and 234 (Summer). In 2025 they ranged from 143 to 166. The largest batch in the directory is Winter 2022, with 398 companies; the smallest is Winter 2006, with 7.

Four batches a year means smaller batches: each 2025 batch had between 143 and 166 companies, against 220 to 398 for the twice-yearly batches of 2021 to 2024. The yearly total has grown again, though: 677 companies are listed for 2026 so far.

The counts come from YC's public startup directory, through the open-source yc-oss mirror of it, pulled on September 13, 2026. YC's own directory showed the same total that day: 6,215 companies, of which 6,213 are in batches from 2005 to 2026. The other two are the Winter 2027 company and one company YC lists with no batch.

The directory lists launched companies YC shows publicly, so it is not a list of every company YC has ever funded. Status labels and counts change as YC updates its listings. We describe companies only with YC's own labels and our own words, never YC's descriptions.

A batch, a status or a company count says nothing about a company's marketing budget, and this page is research, not a prospect list. If you are building a startup yourself, our guide to SEO for startups covers when search is worth the effort, and our page on marketing for technology companies explains how we work.